weight

—weighter, n.

/wayt/, n.

1. the amount or quantity of heaviness or mass; amount a thing weighs.

2. Physics. the force that gravitation exerts upon a body, equal to the mass of the body times the local acceleration of gravity: commonly taken, in a region of constant gravitational acceleration, as a measure of mass.

3. a system of units for expressing heaviness or mass: avoirdupois weight.

4. a unit of heaviness or mass: The pound is a common weight in English-speaking countries.

5. a body of determinate mass, as of metal, for using on a balance or scale in weighing objects, substances, etc.

6. a specific quantity of a substance that is determined by weighing or that weighs a fixed amount: a half-ounce weight of gold dust.

7. any heavy load, mass, or object: Put down that weight and rest your arms.

8. an object used or useful solely because of its heaviness: the weights of a clock.

9. a mental or moral burden, as of care, sorrow, or responsibility: Knowing you are safe takes a weight off my mind.

10. importance, moment, consequence, or effective influence: an opinion of great weight.

11. Statistics. a measure of the relative importance of an item in a statistical population.

12. (of clothing, textiles, etc.)

a. relative heaviness or thickness as related to warmth or to seasonal use (often used in combination): a winter-weight jacket.

b. relative heaviness or thickness as related to use: a bolt of coat-weight woolen cloth.

13. Print. (of type) the degree of blackness or boldness.

14. (esp. in boxing) a division or class to which a contestant belongs according to how much he weighs: two brothers who fight professionally in the same weight.

15. the total amount the jockey, saddle, and leads must weigh on a racehorse during a race, according to the conditions of the race: Jacinto has a weight of 122 pounds in the seventh race.

16. the stress or accent value given a sound, syllable, or word.

17. by weight, according to measurement of heaviness or mass: Rates are determined by weight.

18. carry weight, to have importance or significance; influence: Her opinion is certain to carry weight.

19. pull one's weight, to contribute one's rightful share of work to a project or job: We will finish in time if we each pull our weight. Also, pull one's own weight.

20. throw one's weight around or about, to use one's power and influence, esp. beyond the bounds of propriety, to secure some personal gain.

v.t.

21. to add weight to; load with additional weight: to weight sacks before dumping them overboard.

22. to load (fabrics, threads, etc.) with mineral or other matter to increase the weight or bulk.

23. to burden with or as if with weight (often fol. by down): Financial worries have weighted that family down for years.

24. Statistics. to give a statistical weight to.

25. to bias or slant toward a particular goal or direction; manipulate: The teacher weighted the test so students who had read both books would make the highest marks.

26. to assign (a racehorse) a specific weight to carry in a race: The handicapper weighted Dapper Dan with 128 pounds.

[bef. 1000; ME (n.); OE wiht (c. D wicht, G Gewicht); see WEIGH, -TH¹]

Syn. 10. effect, power, efficacy, import, significance. 23. oppress, encumber, saddle, load.

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I

Gravitational force of attraction on an object, caused by the presence of a massive second object, such as the Earth or Moon.

It is a consequence of Isaac Newton's universal law of gravitation, which states that the force of attraction between two objects is proportional to the product of their masses and inversely proportional to the square of the distance between them. For this reason, objects of greater mass weigh more on the surface of the Earth. On the other hand, an object's weight on the Moon is about one-sixth of its weight on Earth, even though its mass remains the same, because the Moon has less mass and a smaller radius than the Earth and therefore exerts less gravitational force. Weight W is the product of an object's mass m and the acceleration of gravity g at the location of the object, or W = mg. Since weight is a measure of force rather than mass, the units of weight in the International System of Units are newtons (N). In common usage, weight is measured by the gram in the metric system and by the ounce and pound in the U.S. and British systems.

II

(as used in expressions)

atomic weight

equivalent weight

combining weight

formula weight

molecular weight

weight lifting

weight training

weights and measures

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▪ physics

      gravitational force of attraction on an object, caused by the presence of a massive second object, such as the Earth or Moon. Weight is a consequence of the universal law of gravitation: any two objects, because of their masses, attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Thus more massive objects, of course, weigh more in the same location; the farther an object is from the Earth, the smaller is its weight. The weight of an object at the Earth's South Pole is slightly more than its weight at the Equator because the polar radius of the Earth is slightly less than the equatorial radius. Though the mass of an object remains constant, its weight varies according to its location. The smaller mass and radius of the Moon compared with those of the Earth combine to make the same object on the Moon's surface weigh one-sixth the value of its weight on Earth.

      Because of all the mass in the universe, each point of space has a property called the gravitational (gravitation) field at that point, numerically equal to the acceleration of gravity at that point. Alternatively, weight is the product of an object's mass and either the gravitational field or the acceleration of gravity at the point where the object is located.

      Units of weight are those of force, not mass (see force).

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